Waste stripper for label-making machines



E. C. FRISBIE Dec. 26, 1967 WASTE STRIPPER FOR LABEL-MAKING MACHINES 4Sheets-Sheet l Filed June 22, 1965 Dec. 26, 1967 E. c. FRISBIE WASTESTRIPPER FOR LABVELMAKING MACHINES Filed June 22, 1965 Dec. 26, 1967 E.c. FRISBIE 3,360,210

WASTE STRIPPER FOR LABEL-MAKING MACHINES Filed June 22, 1965 4Sheets-Sheet 5 EDWARD C. FRISE/E 1N VENTOR 7' ORNE Y E. C. FRISBIE Dec.26, 1967 4 Sheets-Sheet 4 Filed June 22, 1965 EDWARD C. FRISE/E INVENTORBW MINNIE@ 6@ TTOEWEY United States Patent O 3,360,210 WASTE STRIPPERFOR LABEL-MAKING MACHINES Edward C. Frisbie, Oakland, NJ., assigner toCharles D. Ingraham & Sons, Inc., Nutley, NJ., a corporation of NewJersey Filed June 22, 1965, Ser. No. 465,991 5 Claims. (Cl. 242-65)ABSTRACT OF THE DISCLOSURE Apparatus for automatically stripping wastematerial from an intermittently moving backing strip carryingpressure-sensitive, adhesive labels and winding the strip of wastematerial on a roll. The roll is frictionally driven by a drive rollduring movement of the backing strip and the Waste material strip passesover a spring-biased idler roller which is displaceable in a directionparallel to the movement of the 'backing strip in correspondence withAchanges in the tension of the waste material strip.

This invention -relates to a machine for making pressure-sensitiveadhesive labels and more particularly to a waste stripper forautomatically peeling the waste material from the backing strip afterthe individual labels have been die cut and winding the waste materialon a rewind roll.

Labels of the type to which this invention is directed are made from asupply stock, or web, consisting of a sheet of paper coated with apressure-sensitive adhesive and carried -by a backing strip made ofglassine, or other material, from which the paper can be separatedwithout loss of the adhesive. The web is supplied in roll form, passedthrough a label-making machine and then rewound into a roll. Generally,the web passes through the machine in an intermittent manner between aplaten and a reciprocating die. When the web is stationary, the die isoperated to cut through the paper, but not through the .backing strip,thereby forming a plurality of individual labels of desiredconfiguration. After the individual labels have lbeen formed, it isnecessary to remove the excess paper, or Waste material, from thebacking strip, that is, all of the paper other than the labels. Thus,the rewound roll comprises the backing strip carrying only the labels.

The rewound roll is subsequently fed into other machines which applyprinted matter to the individual labels and/ or automatically remove thelabels from the backing strip and apply them to particular articles. Onthe other hand, certain label-making machines are provided with printersfor applying the printed matter to the labels. In the latter case, thepaper stock may be imprinted before or after the individual labels havebeen die cut.

In any case, it is necessary to remove t-he waste material in suchmanner as to maintain the original registry of the labels carried by thebacking strip. This has been a problem which is not solved by wastestrippers heretofore available and, consequently, a certain percentageof the finished labels are imperfect and must be scrapped.

A waste stripper made in accordance with this invention overcomes theshortcomings of prior such devices and- 3,360,210 Patented Dec. 26, 1967An object of this invention is the provision of a waste stripperadjustably positionable on a label-making machine, which stripperoperates in timed sequence with the intermittent advance of a strip oflabel stock through the machine.

An object of this invention is the provision of a waste stripper forattachment on a machine used to make pressure-sensitive adhesive labelscarried by a backing strip, said waste stripper automatically removing,from the backing strip, the waste material remaining after the formationof the labels and winding such waste material into a roll.

An object of this invention is the provision of a waste stripper forautomatica-ily stripping the waste material from a web passing through alabel-making machine, said Waste stripper comprising `a roll on whichthe waste material is wound, intermittently operated means forfrictionally driving the roll and a spring-biased idler rollerpositioned proximate to the web and over which the strip of wastematerial passes to the said roll, said idler roller I beingspring-biased and movable in a direction parallel to the movement of theweb in correspondence with changes in the tension of the waste materialstrip.

These and other objects and advantages of the invention will becomeapparent from the following description when taken with the accompanyingdrawings. It will be understood, however, that the drawings are forpurposes of illustration and are not to be construed as defining thescope or limits of the invention, reference being had for the latterpurpose to the claims appended hereto.

In the drawings wheein like refrence characters de- -note like parts inthe several views:

FIGURE 1 is a side elevational View of a label-making machine includinga waste stripper made in accordance with this invention and with theconventional machine components shown diagrammatically;

FIGURE 2 is a t-op plan view showing the label stock as it passesthrough the machine;

FIGURE 3 is an enlarged elevational view taken from the left side of thewaste stripper (which side corresponds to that shown in FIGURE 1) andwith a portion of the vertical mounting plate broken away; Y

FIGURE 4 is a similar view taken from the right side of the wastestripper;

FIGURE 5 is a similar view taken from the front of the waste stripperbut with the forward idler roller and its mountings omitted;

`FIGURE 6 is a horizontal cross-sectional view taken along the lineVII-VII of FIGURE l;

FIGURE 7 is a vertical cross-sectional view taken along the lineVII--VII of FIGURE 5; and

FIGURE 8 is a schematic diagram of the circuit for controlling operationof the electromagnetic clutch.

Reference now is made to FIGURE 1, which is a` diagrammatic sideelevation of a label-making machine having attached thereto a Wastestripper made in accordance with this invention. Such machine comprisesa pair of spaced, parallel tracks, or ways, supported on a plurality oflegs 10, only the forward way 11 being visible in this particular View.A supply roll 12, of the label stock, is rotatably positioned at one endof the machine while a rewind roll is positioned at the other end. Thestock, or web 15, consists of paper having one surface coated with apressure-sensitive adhesive and carried by a backing strip, the paperbeing of a grade and thickness desired for thel particular labels andthe backing strip being glassine, wax paper, or the like, so that thepaper adheres thereto to form the webbut yet is readily removabletherefrom by a peeling action. As shown in FIGURE 1, the paperconstitutes the upper portion of the web 15.

To condition the machine for operation, an end of the web is drawn byhand, between the fixed platen 16 and the label-forming die 17, betweena pair of drive rollers 1-8, through the waste stripper made inaccordance with this invention and identified by the numeral 19, andbetween a pair of tension rollers 20, and thence to the rewind roll.Except for the waste stripper, the other operating components of themachine are of conventional design and construction and, therefore, willbe described only briefly. The operation of such components is effectedby suitable mechanical couplings to a main drive shaft 2.1, such driveshaft being rotatably secured to the rear way and rotated continuouslyduring machine operation by an electric motor, not shown. The driverollers 18, generally covered by rubber or other suitable material, arerotated intermittently to pull the web 15 a predetermined extent alongthe platen 16. When the web is stationary, the die 17 is power driventoward the platen, thereby cutting through the upper paper portion ofthe web but not through the backing strip and forming a plurality oflabels of desired configuration. For example, each operation of the diemay form two labels 22 shown in FIGURE 2, which is a plan view of theweb. After the die 17 has been moved out of engagement with the web, thedrive rollers 18 again are rotated to advance the web. It will beapparent that the extent to which the web is advanced, during eachoperating cycle of the drive rollers, will depend upon the size andnumber of the labels to be formed upon each operation of the die. In anyevent, after several label-forming cycles, the paper portion lof the webwhich lies between the die and the waste stripper 19 (identified by theletter (L) in FIGURE 2), will be cut into a plurality of labels, whichlabels adhere to the backing strip.

The tension rollers 20 are continuously rotated by a separate electricmotor 22 but the frictional pulling force exerted thereby upon the webis only suflicient to maintain the web taut to the left of the driverollers 18 when the latter are stationary. IOn the other hand, when thedrive rollers are rotating, the tension rollers 20 move the web throughthe waste stripper and toward the rewind roll 13. The rewind roll 13 maybe rotated in timed sequence with the movement of the web, oralternatively, the rewind roll can be rotated by suitable friction meanswhereby the web is rewound smoothly even though it is movedintermittently through the machine.

With continued reference to FIGURE 1, the waste stripper comprises aforward idler roller 25, a rear idler roller 26, a waste roller 27 and adrive roller 28. At the beginning of machine operation, the operatorpeels the waste material from the web, in the region of the stripper,passes such waste strip 29 about the idler rollers 26 and 25, betweenthe rollers 27 and 28, and attaches the end to the waste roller 27 as bymeans of a piece of adhesive tape. A more detailed description of thewaste stripper is given hereinbelow. Sufiice to say, for the present,that the drive roller 28 is rotated during the time intervals when theweb is advanced and that the waste roller is carried by a shaft which isslidably movable within aligned, vertical slots formed in the spaced,upper ends of the stripper, only the slot 30 being visible in FIGURE 1.Normally, then, the waste roller 27 is in surface contact with the driveroller 28, the latter having a roughened surface formed, for example, asby a sheet of emery paper cemented thereto. Thus, the waste roller 27 isrotated, frictionally, by the drive roller 28 and moves upwardly as thelayer of waste material is built up thereon. Further the rear idlerroller 2.6 is spring-biased and supported in such manner that it canmove in either direction in a plane parallel to the web in response tochanges in the tension of the waste material strip. The Waste stripperis positionable along the machine ways and is secured in a desired fixedposition as by means of the bolts 31.

It will be apparent, then, that the portion of the web which has passedthrough the waste stripper will comprise only the individual labelscarried by the backing strip. Such portion of the web is illustrated bythe dimension (M) in FIGURE 2, in which figure the backing strip isidentified by the numeral 33t.

Before passing on to a detailed description of the waste stripper,attention is directed to the wheel 34 carrying a peripheral shoe 35having an arcuate length of some 180 degrees. By means of a suitablegearing arrangement, this wheel rotates continuously during machineoperation and effects the closing and opening of the normallyopenedcontacts of a micro switch 36, which switch is secured in fixed positionon the machine. Closure of the micro switch contacts energizes anelectro-magnetic clutch associated with the drive roller 28 of the wastestripper so that the drive roller is rotated only during the timeperiods when the web is advanced along the machine.

Reference now is made to FIGURES 3-5 which are enlarged elevationalviews of the waste stripper with portions of the forward mounting platesbroken away in FIGURES 3 and 4. FIGURE 3 is taken from the left side(corresponding to that shown in FIGURE 1), FIGURE 4 is taken from theright side and FIGURE 5 is taken from the front side, that is, lookingin the direction of the web movement as shown in FIGURE l. Thecomponents of the stripper are carried by a pair of vertical mountingplates 40, 40', which span the ways 11, 11 and which are secured infixed position to the corresponding ways by the bolts 31 and 31. Securedto the upper ends of these plates, as by the sets of bolts `42, 42', arebifurcated end pieces forming the aligned vertical slots 30, 30. Thewaste rewind roller 27 is secured to a shaft 43 which is slidable withinthe slots 30, 30, axial movement of the shaft being limited by the endnuts 44, 44 threaded thereon. The drive roller 28 also is secured to ashaft 45 passing through aligned bearing holes formed in the twomounting plates, said shaft having an end nut 46 threaded on an end anda bevel gear 47 secured to the other end.

Secured to the vertical front edges of the mounting plates 40, 40 are apair of bearing blocks 50, 50 for the shaft of an additional idlerroller 51. Secured to the inclined front edges of the mounting platesare a pair of rectangular blocks 52, 52 which are omitted from FIGURE 5for clarity of disclosure. These blocks are of identical constructionand only the construction of one such block will now be described withspecific reference to FIGURE 3. A transverse slot is formed through therectangular block 52 for receiving the square bearing block 53. Suchblock is adjustably positioned within the slot by means of an adjustingscrew `54 threaded through a hole formed in the lower end of the block,which screw is retained in the set position by a locking nut 55. Acompression spring 56 loosely encircles the shank por- `tion of a headedpin 57, which pin is slidable within a hole formed in the other end ofthe block 52. Thus, the bearing block 53 is spring-biased to the lrightand can move within the slot in response to changes in the tension ofthe waste material strip 29, passing over the roller 25. This roller issecured to a reduced-diameter shaft having one end passing into a boreformed in the bearing block 53. The described arrangement can best beunderstood by reference to FIGURE 6, which shows the square bearingblocks 53, 53 passing through the slots of the respective rectangularblocks 52, 52 The idler roller 25, here shown broken away, is secured tothe shaft 58 having its ends journalled in the bearing blocks 53, 53'.

Reverting back to FIGURES 3-5, the web 15 is supported by a horizontalplate 60 secured in fixed position to the two mounting plates and havinga downwardly offset forward end serving as a guide lip. Seen through thebroken away portion of the mounting plate 40, FIGURE 3, is thespringbiased rear idler lroller 26, the furthermost end of which isrotatably and removably carried by a slide -blgock 61 disposed proximateto the inner surface of the other mounting plate 40. A first guide ypost62,

secured in fixed position on the mounting plate 40', is

agarra@ provided with a clearance hole accommodating the rod 63 whichhas an end force-fitted into a hole formed in the slide block 61. Afirst compression spring 64 loosely encircles the rod 63 and is confinedbetween the slide Iblock and the post 62. A second, l-onger rod 65 isslidable within a hole formed in a second guide post 66, `which also issecured in fixed position on the mounting plate 40'. The left end of therod 65 is force-fitted into a hole formed in the slide block 61. Asecond compression spring 67 loosely encircles the rod 65 and isconfined between the post 66 and an adjustable collar 68, which issecured in the desired position by a set screw, thereby to apply apredetermined compression to the spring 67. It will `be noted that thewaste material strip 29 passes over the idler roller 26. Thus, as thetension on the waste material is increased, the idler roller 26 and thesupporting guide block 61 lwill move to the right against the biasingforce of the spring 67. Such movement of the idler roller 26 is axial ofthe web 15 -by reason of a similar assembly of the roller-supportingmechanism positioned proximate to the inner wall of the other mountingplate. Such mechanism is shown in FIGURE 4 with corresponding partsidentified iby primed reference numbers. The two ends of the rods 65 and65', which project beyond the respective guide posts 62, 62, have atransverse flat tie -bar 70 secured thereto, as by screws. v

The symmetrical construction and assembly of th spring-biasedarrangement supporting the rear idler roller 26 of the lwaste stripperis shown in FIGURE 6, which is a horizontal cross-sectional view takenalong the line VI-VI of FIGURE 3 but with a portion of the forward idlerroller and its supporting shaft 58 broken away. The transversely alignedfixed guide posts, 62, 62 and 66, 66' are secured in fixed positions tothe respective, vertical mounting plates and 40. The slide .blocks 61,61 are provided with facing, longitudinal channels, each channelincluding a vertical portion extending to the upper surface of thecorresponding slide Iblock. The rear idler roller 26 is rotatable withthe longitudinal portions of the channels and is inserted into positionby passing the ends thereof through the vertical portions of the slots.As is apparent from FIGURES 3 and 4, the ends of the idler roller 26 areretained in the longitudinal portions of the slide block channels by thetension exerted against the roller Aby the strip 29 of the wastematerial. As this tension is increased, or decreased, the slide blocksand the idler roller move linearly in a plan parallel to that of theweb.

Referring now specifically to FIGURES 4 and 5, an electro-magneticclutch 72 has an integral collar 73, which collar is secured to theshaft 74 passing through aligned holes provided in the bearing blocks 75and 76, said bearing blocks being secured to the vertical mounting plate40. A bevel gear 77 (see FIGURE 4) is secured to the shaft 74 and is inmesh with the similar bevel gear 47, which is secured to the shaftcarrying `the drive roller 28 (see FIGURE 5). A sprocket wheel 78normally is freely rotatable about the`shaft 74 and 4is connected by adrive chain 79 to the sprocket wheel 80, the latter being secured to themain drive shaft 21 of the machine. Although the main drive shaft 21rotates continuously during operation of the machine, the drive shaft74, carrying the bevel gear 77, rotates only when the electrornag neticclutch 72 is energized by a voltage applied to the leads 81, that is,the sprocket wheel 7 8 rotates freely about its shaft 74 when the clutchis deenergized and such sprocket wheel is mechanically coupled to itsshaft by means of the collar 73 and the clutch when the latter isenergized.

As has been described with reference to FIGURE 1, the wheel 34 isrotated by the main drive shaft 21 and carries a -shoe 35 which effectsa closing and opening of the electrical contacts of the micro switch 36.The timed operating sequence of the machine is such that the contacts ofthe micro swit-ch are closed when the drive rollers 18 are rotated toadvance the web 15. After the web has been advanced, the shoe 35 permitsthe micro switch contacts to return to the open position. The microswitch contacts control the operation of the magnetic clutch as will nowbe described with reference to the schematic circuit diagram of FIGURE8. Here, a voltage obtained from a conventional power line is applied tothe rectifier -83 upon closure of the line switch 84. The operatingsolenoid of the electro-magnetic clutch 72 is connected across theoutput diagonals of the rectifier through the contacts of the microswitch 36. As shown, the operating pin 85, of the micro switch, isdepressed by the shoe 35, the switch contacts are closed and the clutchis energized, whereby the sprocket wheel 78 is mechanically coupled tothe shaft 74. When the trailing edge of the shoe V35 passes beyond thepin 85, the switch contacts are opened, the clutch is deenergized andthe sprocket wheel is decoupled from the shaft 74; the micro switchincorporating a suitable spring-biasing arrangement which normallyretains the contacts to open position, as is well known.

rIt will be clear, now, that the drive roller 28, of the waste stripper(see particularly FIGURE 4), is rotated only during the time period whenthe web 15 is advancing and that the rotation of this driveroller-results in the strip 29, of the waste material, being wound onthe waste roller 27. Further, as the diameterof the rolled waste stripincreases, the shaft 43, carrying the waste roller 27, slides upwardlywithin the aligned slots of the bifurcated end pieces secured to thevertical mounting plates of the waste stripper.

The operation of the waste stripper will best berunderstood by referenceto FIGURE 7, which is a vertical cross-sectional view taken along theline VII-VII .of FIGURE 5. The drive roller 28 is rotated only duringthose portions of the machine operating cycle when the web 15 is beingadvanced. Thus, during movement of the web, the strip 29 of the wastematerial is peeled therefrom and wound upon the waste rewind roller 27.When the web is stationary, the drive roll also lis stationary. It Iwillbe noted that the slide block 61 is biased t0 the right by the spring 64and to the left by the spring 67. The adjustable collar 68, is securedto the rod 65 to compress the spring -67 as is necessary in order to setthe normal position of the idler roller 26. Such adjustment of thenormal, or working, positionof the idler roller is desirable to fix theaxial line along which the Waste material is peeled from the web, sincethe initial force required at the start of each peeling operationdepends upon the size of the particular labels, the character of thebacking strip and the particular pressure-sensitiveadhesive. Thedescribed vadjustment obviates the need to move the entire wastestripper and/or other operating components of the machine in order toeffect an optimum release of the waste material from the backing strip.

Once the normal position of the idler roller 26 has been set foroperation with a particular web, the slide block 61 is free to move tothe left or to the right in response to changes in the tension of thewaste strip 29 effective against the idler roller 26. Such tensionchanges may occur due to varying adhesion of the waste material and thebacking strip at the peeling point, the build up of the waste materialstrip on the roller 27, or the difference in the force required to startthe peeling operation as compared to that after the peeling operationhas been started. In any event, the described floating arrangement ofthe slide block provides compensation for these variable factors,thereby effecting a uniform release of the waste material from thebacking strip. This factor, together with the fact that the strippingoperation is performed only during the period when the web is movingthrough the machine, eliminates the possibility of distorting thebacking strip carrying the formed labels thereon. Obviously, distortionof the backing strip alters the original registry of the labels and mayrender such label- 7 carrying strip unsatisfactory for subsequent use ina printing machine or a machine for automatically removing the labelsfrom the strip.

In the illustrated construction and arrangement of the waste stripper,the rear idler roller is shown of a relatively small diameter and spacedsomewhat from the surface of the web. Such arrangement has been found tobe, practical for use on label-making machines wherein the ratio of thelabel area to that of the waste material is relatively high. In machineswherein this ratio is smaller, itis desirable to use a roller of largerdiameter with its surface positioned in closer proximity to the websurface. Also, certain label-making machines have gear racks secured tothe top surfaces of the ways. In such instances, the waste stripper canadvantageously be provided with a conventional meshing gear rotatable bya handle to position the stripper along the rack and a locking lever forsecuring it in the desired position.

Having now described the construction and operation of my novel wast-estripper, those skilled in this art will will be able to make Variouschanges and modifications without thereby departing from the scope andspirit of the invention as recited in the following claims.

I claim:

1. A waste stripper comprising,

(a) a pair of vertical, spaced mounting plates,

(b) a horizontal plate spanning said mounting plates for supporting aweb of label-making stock,

(c) a rewind roller carried 'by ya shaft journaled for rotation withinaligned, vertical slots formed at the upper ends of the mounting plates,

(d) a drive roller rotatably carried by the mounting plates `andpositioned to support said rewind roller,

(e) a first idler roller having la surface proximate to said horizontalplate,

(f) `bearing means supporting said first idler roller for rotation aboutan axis parallel to the plane of said horizontal plate,

(g) adjustable spring-biasing means for positioning said bearing meansin a predetermined position while affording linear movement thereofparallel to the horizontal plate,

(h) a second `idler roller, and

(i) spring-'biased Ibearing means carried by the said vertical mountingIplates and supporting said second idler roller Ifor rotation rabout anaxis spaced a greater distance from the horizontal plate than that ofthe said first idler roller.

2. The invention as recited in claim 1, including a drive shaft carriedby one of said vertical mounting plates, means coupling said dri-veshaft to the shaft of said drive roller for simultaneous rotationthereof, and means including -an electro-magnetic clutch carried by saiddrive shaft for effecting rotation thereof by a remotely positionedpower driven shaft.

3. The invention as recited in claim 2, wherein the said bearing meanssupporting the first idler roller comprises a pair of spaced slideblocks receiving the ends of said roller; and wherein the saidadjustable spring-biasing means comprises axially-aligned sets of rods,each set of rods being slidably supported by spaced posts secured to thevertical mounting plates and having adjacentlydisposed ends secured toan associated slide block; compressing springs carried by each of saidrods; and collar means carried by one rod `of each set and securable infixed position thereon to apply a predetermined amount of compressiont-o the corresponding spring.

4. In a pressure-sensitive adhesive label-making machine of the classhaving a main drive which rotates continuously during machine operationand wherein a web of la'bel stock is advanced intermittently duringformation of the labels, the combination of,

(a) a waste stripper carried by the machine and through vwhich the webpasses after the formation of the labels, said stripper comprising afirst idler roller having a surface proximate to the web, a second idlerr-oller offset `from the first idler roller along the web axis, a rewindroller on Awhich a strip of waste material is wound after it passes overboth of said idler rollers, a drive roller carried by a shaft andsupporting the roll yof waste material as it is wound on said rewindroller, a drive shaft rotatably coupled to the shaft carrying the driveroller, said drive shaft carrying an electro-magnetic clutch,

(b) means rotatably connecting the said drive shaft of the wastestripper to the main drive shaft of the machine when the said clutch isenergized.

(c) a normally-open switch carried by the machine,

(d) switch-actuating means effecting operation of said switch in timedsequence with the advance of the we'b, and

(e) leads connecting the clutch to a source of voltage upon closure ofthe said switch, the arrangement being such that the clutch is energizedonly when the web is advancing whereby the said drive roller rotates thesaid rewind roller to wind the strip of waste material thereonsimultaneously with the advance 0f the web through the waste stripper.

5. The invention Ias recited in claim 4, wherein the said -first idlerroller is carried by spring-backed bearing means movable in a planeparallel to that of the web in correspondence with changes in thetension of the waste lmaterial strip as it is wound on the said rewindroller.

References Cited UNITED STATES PATENTS 942,164 12/ 1909 Bolton 242-67.3X 1,181,937 5/1916 Stevens 242--65 1,929,087 1'0/'1'933 Wood 242-7531,985,524. 12/1934 Stacey 242-673 2,743,064 4/1956 LeFebure et al.242-673 X 3,055,606 9/-1962 Alden 242-673 3,178,123 4/1965` Buddecke242-673 X 3,191,884 6/1965 West et al. 242-67.1

GEORGE F. MAUTZ, Primary Examiner.

1. A WASTE STRIPPER COMPRISING, (A) A PAIR OF VERTICAL, SPACED MOUNTINGPLATES, (B) A HORIZONTAL PLATE SPANNING SAID MOUNTING PLATES FORSUPPORTING A WEB OF LABEL-MAKING STOCK, (C) A REWIND ROLLER CARRIED BY ASHAFT JOURNALED FOR ROTATION WITHIN ALIGNED, VERTICAL SLOTS FORMED ATTHE UPPER ENDS OF THE MOUNTING PLATES, (D) A DRIVE ROLLER ROTATABLYCARRIED BY THE MOUNTING PLATES AND POSITIONED TO SUPPORT SAID REWINDROLLER, (E) A FIRST IDLER ROLLER HAVING A SURFACE PROXIMATE TO SAIDHORIZONTAL PLATE, (F) BEARING MEANS SUPPORTING SAID FIRST IDLER ROLLERFOR ROTATION ABOUT AN AXIS PARALLEL TO THE PLANE OF SAID HORIZONTALPLATE, (G) ADJUSTABLE SPRING-BIASING MEANS FOR POSITIONING SAID BEARINGMEANS IN A PREDETERMINED POSITION WHILE AFFORDING LINEAR MOVEMENTTHEREOF PARALLEL TO THE HORIZONTAL PLATE, (H) A SECOND IDLER ROLLER, AND(I) SPRING-BIASED BEARING MEANS CARRIED BY THE SAID VERTICAL MOUNTINGPLATES AND SUPPORTING SAID SECOND IDLER ROLLER FOR ROTATION ABOUT ANAXIS SPACED A GREATER DISTANCE FROM THE HORIZONTAL PLATE THAN THAT OFTHE SAID FIRST IDLER ROLLER.